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Hydroboration of Alkenes and Alkynes with Aza‐ nido ‐decaboranes
Author(s) -
Paetzold Peter,
Leuschner Ellen
Publication year - 2002
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/1521-3749(200203)628:3<658::aid-zaac658>3.0.co;2-d
Subject(s) - boranes , hydroboration , chemistry , decaborane , borane , trimethylsilyl , stereochemistry , medicinal chemistry , organic chemistry , boron , catalysis
The 6‐aza‐ nido ‐decaboranes RNB 9 H 11 ( 1a—d ; R = H, Ph, 4‐C 6 H 4 Me, 4‐C 6 H 4 Cl) act as 1, 2‐hydroboration agents via their 9‐BH vertex, giving products RNB 9 H 10 R′. The boranes 1a, b and 3‐hexyne yield the 9‐(1‐ethyl‐1‐butenyl)‐6‐aza‐ nido ‐decaboranes 2a, b (R′ = CEt = CHEt). 2, 3‐Dimethyl‐2‐butene is hydroborated by 1a—d under formation of the 9‐(1, 1, 2‐trimethylpropyl)‐6‐aza‐ nido ‐decaboranes 3a—d (R′ = —CMe 2 —CHMe 2 ). With the boranes 1a—c and (trimethylsilyl)ethene, a 85:15 mixture of the products (RNB 9 H 10 )CH 2 CH 2 (SiMe 3 )( 4a—c ) and their chiral isomers (RNB 9 H 10 )CH(SiMe 3 )CH 3 ( 5a—c ) is obtained. The action of BH 3 (SMe 2 ) on the mixtures 4b/5b or 4c/5c results in a closure of the nido ‐NB 9 skeleton of 4b or 4c , respectively, with a closo ‐NB 11 skeleton of the products RNB 11 H 10 R′ ( 6b or 6c;R′ = CH 2 CH 2 (SiMe 3 )); R′ is found in position 7 of 6b, c . All products of the type 2—6 are characterised by NMR.